In printmaking, an edition is a number of prints struck from one plate, usually at the same time. This is the meaning covered by this article. This may be a limited edition, with a fixed number of impressions produced on the understanding that no further impressions (copies) will be produced later, or an open edition limited only by the number that can be sold or produced before the plate wears. Most modern artists produce only limited editions, normally signed by the artist in pencil, and numbered as say 67/100 to show the unique number of that impression and the total edition size.
Edition is a particular form or version of a published text. For example: "a paperback edition"